For certain drill accessories, such as U.S. Pat. Ser. No. 10/680,146, titled drill accessory, they all have a rotatable storage barrel mounted on an elongate drive shaft to provide a storage area for other bits. In FIG. 1, 1 is the shaft, 2 is the storage barrel.
Because each bit is in a different shape, different weight, and usually there is an empty reserved recess on the storage barrel 2 for the bit that is being positioned on the shaft 1 and is being used, the barrel 2 is not balanced. Because of the friction, the storage barrel 2 has the trend to rotate with the shaft 1 when the shaft 1 is rotating. Once the storage barrel 2 rotates, the tool 10 and the drill 6 (in FIG. 1) will be instable. We need a way to make the barrel 2 stationary when the drive shaft 1 is rotating. One way is to use a hand to hold the barrel 2. This way always requires a hand available, not the best solution. Another solution mentioned in the patent application titled drill accessory, Ser. No. 10/680,146, is inserting a U shape spring between the storage barrel 2 and the drill body 6. This solution has some drawbacks: first, it's very hard for a U shape spring to fit all drills properly. Secondly, a U shape spring protrudes from a drill chuck, not safe and attractive. This invention provides a better solution.